Understanding the biological function of fluorescent proteins in corals

• Project/Area Number: 18K19240
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 40:Forestry and forest products science, applied aquatic science, and related fields
• Research Institution: National Institute for Basic Biology
• Principal Investigator: Takahashi Shunichi 基礎生物学研究所, 環境光生物学研究部門, 准教授 (80620153)
• Project Period (FY): 2018-06-29 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000); Fiscal Year 2019: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000); Fiscal Year 2018: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
• Keywords: サンゴ / 蛍光 / プランクトン / 走光性 / 捕食 / 誘引 / 白化 / 回復 / 蛍光タンパク質 / 海洋性微生物 / 海洋微生物

Outline of Final Research Achievements

This project studied the physiological significance of coral’s fluorescence proteins and achieved two important outcomes. (1) The green fluorescence emitted by coral’s green fluorescence proteins (GFP) attracts free-living zooxanthellae (symbiotic dinoflagellates) due to the combination of negative phototaxis towards the light source and positive phototaxis towards the green fluorescence (Aihara et al. 2019 PNAS). (2) Cultured copepods and sampled plankton from coral reefs both show positive phototaxis towards light from the green region of the light spectrum but with no negative phototaxis observed to any colored light at all light intensities tested. Therefore, in contrast to symbiotic dinoflagellates, copepods and plankton were not attracted by coral’s green fluorescence when in the presence of a green fluorescence-inducing light source.

Academic Significance and Societal Importance of the Research Achievements

サンゴの緑色蛍光タンパク質（GFP)由来の緑色蛍光が、共生する褐虫藻の誘引に働くことが示された。これは、褐虫藻の光源（自然界では太陽光）に対する負の走光性と、サンゴ緑色蛍光に対する正の走光性に起因する。これは、サンゴの蛍光が、褐虫藻の誘引に働くことを実験的に示した初めての研究結果である。この成果は、論文として国際誌の米国科学アカデミー紀要（Aihara et al. 2019 PNAS)に発表した。また、この成果は、様々なメディア（新聞、ニュース、ネットニュース）で紹介された。

Research Products

• [Int'l Joint Research] James Cook University(オーストラリア)
• [Int'l Joint Research] James Cook University(オーストラリア)
• [Journal Article] Loss of symbiont infectivity following thermal stress can be a factor limiting recovery from bleaching in cnidarians (2020)
  • Author(s): Mariko Kishimoto, Andrew H. Baird, Shinichiro Maruyama, Jun Minagawa & Shunichi Takahash
  • Journal Title: The ISME Journal Volume: 14 Issue: 12 Pages: 3149-3152
  • DOI: 10.1038/s41396-020-00742-8
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Transcriptomic analyses highlight the likely metabolic consequences of colonization of a cnidarian host by native or non-native Symbiodinium species (2019)
  • Author(s): Lin Mei-Fang、Takahashi Shunichi、Foret Sylvain、Davy Simon K.、Miller David J.
  • Journal Title: Biology Open Volume: 8
  • DOI: 10.1242/bio.038281
  • Peer Reviewed / Open Access
• [Journal Article] Green fluorescence from cnidarian hosts attracts symbiotic algae (2019)
  • Author(s): Yusuke Aihara, Shinichiro Maruyama, Andrew H. Baird, Akira Iguchi, Shunichi Takahashi, Jun Minagawa
  • Journal Title: Proceedings of the National Academy of Sciences of the United State of America Volume: 116 Issue: 6 Pages: 2118-2123
  • DOI: 10.1073/pnas.1812257116
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] なぜサンゴは白化から回復しないのか (2019)
  • Author(s): 岸本真理子、丸山真一朗、皆川純、高橋俊一
  • Organizer: 日本サンゴ礁学会22回大会
• [Presentation] サンゴの緑色蛍光による褐虫藻の誘引 (2018)
  • Author(s): 相原悠介、丸山 真一朗、Andrew Baird、井口 亮、高橋 俊一、皆川純
  • Organizer: 日本サンゴ礁学会２１回大会
• [Presentation] サンゴに共生する褐虫藻：動から静への変化がもたらすもの (2018)
  • Author(s): 高橋俊一
  • Organizer: 日本共生生物学会第2回大会Symbio2018Kobe
  • Invited
• [Book] 生物科学 (2018)
  • Author(s): 高橋俊一
  • Publisher: 農山漁村文化協会(農文協)
• [Remarks]
  • URL: http://www.nibb.ac.jp/press/2019/01/22.html